Hydroxycitric acid
Encyclopedia
Hydroxycitric acid is a derivative of citric acid
that is found in a variety of tropical plants including Garcinia cambogia and Hibiscus subdariffa. Laboratory and animal studies of HCA have produced results that indicate a potential for modulation of lipid metabolism; consequently HCA is an ingredient in some weight loss products and dietary supplements. However, a clinical study has demonstrated that HCA has no effect in terms of weight loss or reduction of fat mass.
One isomer
of HCA, known as (2S,3R)-HCA, inhibits pancreatic alpha-amylase
and intestinal alpha-glucosidase
, leading to a reduction in carbohydrate metabolism in vitro
. In a study in Zucker rats, which are genetically predisposed to obesity, Garcinia cambogia extract containing HCA showed that high doses led to significant suppression of epididymal fat accumulation, but also caused potent testicular atrophy and toxicity. However, this study has been criticized because of possible contamination of the HCA used and various design flaws.
Citric acid
Citric acid is a weak organic acid. It is a natural preservative/conservative and is also used to add an acidic, or sour, taste to foods and soft drinks...
that is found in a variety of tropical plants including Garcinia cambogia and Hibiscus subdariffa. Laboratory and animal studies of HCA have produced results that indicate a potential for modulation of lipid metabolism; consequently HCA is an ingredient in some weight loss products and dietary supplements. However, a clinical study has demonstrated that HCA has no effect in terms of weight loss or reduction of fat mass.
One isomer
Isomer
In chemistry, isomers are compounds with the same molecular formula but different structural formulas. Isomers do not necessarily share similar properties, unless they also have the same functional groups. There are many different classes of isomers, like stereoisomers, enantiomers, geometrical...
of HCA, known as (2S,3R)-HCA, inhibits pancreatic alpha-amylase
Alpha-Amylase
α-Amylase is an enzyme that hydrolyses alpha-bonds of large alpha-linked polysaccharides such as starch and glycogen, yielding glucose and maltose. It is the major form of amylase found in humans and other mammals...
and intestinal alpha-glucosidase
Alpha-glucosidase
Alpha-glucosidase is a glucosidase acting upon 1,4-alpha bonds. This is in contrast to beta-glucosidase.The term maltase, which refers to an enzyme cleaving maltose, is nearly equivalent.Types include:* Acid alpha-glucosidase* neutral** GANAB** GANC...
, leading to a reduction in carbohydrate metabolism in vitro
In vitro
In vitro refers to studies in experimental biology that are conducted using components of an organism that have been isolated from their usual biological context in order to permit a more detailed or more convenient analysis than can be done with whole organisms. Colloquially, these experiments...
. In a study in Zucker rats, which are genetically predisposed to obesity, Garcinia cambogia extract containing HCA showed that high doses led to significant suppression of epididymal fat accumulation, but also caused potent testicular atrophy and toxicity. However, this study has been criticized because of possible contamination of the HCA used and various design flaws.